# Homework Help: Velocity as a Function of position

1. Jan 25, 2005

### Drey0287

At an outdoor market, a bunch of bananas is set into oscillatory motion with an amplitude of 20.0cm on a spring with a spring constant of 16.0 N/m. It is observed that the maximum speed of the bananas is 40.0 cm/s. What is the weight of the bananas in newtons?

2. Jan 25, 2005

### Sirus

This is an isolated system, so mechanical energy is conserved.

$$E_{mechanical}=E_{kinetic}+E_{potential}$$

The maximum speed will occur at x=0 (x is the distance the spring is stretched from its equilibrium position). Also,

$$E_{potential}=\frac{1}{2}kx^2$$

and as you probably know

$$E_{kinetic}=\frac{1}{2}mv^2$$

You should be able to figure it out using that.